Breast Cancer
Conditions
Keywords
Breast cancer, Breast conserving surgery, Radiotherapy, Pendulous breasts
Brief summary
We hypothesize that for large pendulous breasts, breast irradiation in supine and prone position are equivalent with regard to coverage of the PTV, but with a better dose homogeneity in prone position and a smaller radiation exposure of lung and heart.The purpose of this study is to compare the 3-D dose distribution in PTV(Planning Target Volume) and normal tissues in prone position versus supine position.
Detailed description
Local excision followed by adjuvant radiotherapy has become standard treatment for women with early-stage breast cancer. Adjuvant radiotherapy may encounter technical difficulties in patients with pendulous breasts when treated in supine position. Based upon literature and our own preliminary experiences, we hypothesize that for large pendulous breasts, breast irradiation in supine and prone position are equivalent with regard to coverage of the PTV, but with a better dose homogeneity in prone position and a smaller radiation exposure of lung and heart. However, no quantitative data are yet available to test this hypothesis. Therefore, the aim of our study is to compare the 3-D dose distribution in PTV and normal tissues in prone position versus supine position. For treatment in prone-position an in-house developed device, the mammaboard was used.
Interventions
DEVICEMamma board
use of mamma board during radiotherapy
Sponsors
Maastricht University
Maastricht Radiation Oncology
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients should have had breast-conserving surgery for breast cancer or DCIS (Ductal Carcinoma in Situ) * No indication for radiotherapy of regional nodes * Large, pendulous breasts (bra size D and over)
Exclusion criteria
* Regional radiotherapy is indicated * Unable to lie in prone position
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dose Homogeneity 1: PTV | 1 day after treatment planning | Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) and normal tissues in prone position versus supine position |
| Dose Homogeneity 2: V105% and V107% | 1 day after treatment planning | Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) in prone position versus supine position |
| Dose Homogeneity 3: V95 % | 1 day after treatment planning | PTV coverage (% of PTV \< 95% of prescribed dose) in prone position versus supine position |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| PTV Coverage in Organs at Risk: MLD (Gy) | during treatment planning | Doses in organs at risk: lung MLD (Mean Lung Dose) |
| PTV Coverage in Organs at Risk: Heart V30 | during treatment planning | Doses in organs at risk: heart V30: the volumes (%) of the heart that received \>= 30Gy |
Countries
Netherlands
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Group 1 Mamma board | 10 |
| Total | 10 |
Baseline characteristics
| Characteristic | Group 1 |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 10 Participants |
| Region of Enrollment Netherlands | 10 participants |
| Sex: Female, Male Female | 10 Participants |
| Sex: Female, Male Male | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 10 |
| serious Total, serious adverse events | 0 / 10 |
Outcome results
Primary
Dose Homogeneity 1: PTV
Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) and normal tissues in prone position versus supine position
Time frame: 1 day after treatment planning
Population: To investigate dose homogeneity and maximum doses, Dmin (minimum Dose), Dmax (maximum Dose) and Dmean (mean Dose) were calculated for prone position versus supine position.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prone | Dose Homogeneity 1: PTV | Dmin (Gy) PTV | 9.8 Gy | Standard Deviation 6.7 |
| Prone | Dose Homogeneity 1: PTV | Dmean (Gy) PTV | 48.2 Gy | Standard Deviation 1.2 |
| Prone | Dose Homogeneity 1: PTV | Dmax (Gy) PTV | 53.6 Gy | Standard Deviation 0.6 |
| Supine | Dose Homogeneity 1: PTV | Dmin (Gy) PTV | 8.2 Gy | Standard Deviation 5.6 |
| Supine | Dose Homogeneity 1: PTV | Dmean (Gy) PTV | 49.8 Gy | Standard Deviation 0.8 |
| Supine | Dose Homogeneity 1: PTV | Dmax (Gy) PTV | 54.8 Gy | Standard Deviation 1.4 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Primary
Dose Homogeneity 2: V105% and V107%
Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) in prone position versus supine position
Time frame: 1 day after treatment planning
Population: To investigate dose homogeneity V105% (volume of tissue receiving more than 105% of the prescribed dose) and V107% (volume of tissue receiving more than 107% of the prescribed dose) were calculated for prone position versus supine position.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prone | Dose Homogeneity 2: V105% and V107% | V105% PTV | 1.5 cc | Standard Deviation 1.2 |
| Prone | Dose Homogeneity 2: V105% and V107% | V107% PTV | 0.1 cc | Standard Deviation 0.3 |
| Supine | Dose Homogeneity 2: V105% and V107% | V105% PTV | 9.1 cc | Standard Deviation 9.9 |
| Supine | Dose Homogeneity 2: V105% and V107% | V107% PTV | 2.8 cc | Standard Deviation 4.8 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Primary
Dose Homogeneity 3: V95 %
PTV coverage (% of PTV \< 95% of prescribed dose) in prone position versus supine position
Time frame: 1 day after treatment planning
Population: To investigate dose homogeneity V105% (volume of tissue receiving more than 105% of the prescribed dose) and V107% (volume of tissue receiving more than 107% of the prescribed dose) were calculated for prone position versus supine position.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prone | Dose Homogeneity 3: V95 % | V95%PTV | 78.6 cc | Standard Deviation 5.6 |
| Prone | Dose Homogeneity 3: V95 % | V95%CTV | 85.0 cc | Standard Deviation 4.2 |
| Supine | Dose Homogeneity 3: V95 % | V95%PTV | 91.4 cc | Standard Deviation 4.1 |
| Supine | Dose Homogeneity 3: V95 % | V95%CTV | 93.3 cc | Standard Deviation 4 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
PTV Coverage in Organs at Risk: Heart V30
Doses in organs at risk: heart V30: the volumes (%) of the heart that received \>= 30Gy
Time frame: during treatment planning
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prone | PTV Coverage in Organs at Risk: Heart V30 | 2.4 percentage of V30 | Standard Deviation 3 |
| Supine | PTV Coverage in Organs at Risk: Heart V30 | 7.3 percentage of V30 | Standard Deviation 4.6 |
p-value: <0.05Wilcoxon (Mann-Whitney)
Secondary
PTV Coverage in Organs at Risk: MLD (Gy)
Doses in organs at risk: lung MLD (Mean Lung Dose)
Time frame: during treatment planning
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prone | PTV Coverage in Organs at Risk: MLD (Gy) | 0.9 Gy | Standard Deviation 0.6 |
| Supine | PTV Coverage in Organs at Risk: MLD (Gy) | 4.1 Gy | Standard Deviation 1.6 |
p-value: <0.05Wilcoxon (Mann-Whitney)